U.S. patent application number 12/496162 was filed with the patent office on 2010-07-01 for golf club head.
This patent application is currently assigned to BRIDGESTONE SPORTS CO., LTD.. Invention is credited to Wataru Ban.
Application Number | 20100167837 12/496162 |
Document ID | / |
Family ID | 42285636 |
Filed Date | 2010-07-01 |
United States Patent
Application |
20100167837 |
Kind Code |
A1 |
Ban; Wataru |
July 1, 2010 |
GOLF CLUB HEAD
Abstract
A golf club head of this invention includes a head body, a
weight member attached to the head body, and a fixing unit to fix
the weight member at one of a plurality of attachment positions of
the head body. The plurality of attachment positions are located on
a virtual cylindrical surface having the axis of a shaft to be
mounted to the golf club head as a center.
Inventors: |
Ban; Wataru; (Saitama,
JP) |
Correspondence
Address: |
SUGHRUE MION, PLLC
2100 PENNSYLVANIA AVENUE, N.W., SUITE 800
WASHINGTON
DC
20037
US
|
Assignee: |
BRIDGESTONE SPORTS CO.,
LTD.
Tokyo
JP
|
Family ID: |
42285636 |
Appl. No.: |
12/496162 |
Filed: |
July 1, 2009 |
Current U.S.
Class: |
473/336 |
Current CPC
Class: |
A63B 53/0466 20130101;
A63B 53/0433 20200801; A63B 53/04 20130101; A63B 60/02 20151001;
A63B 2053/0491 20130101; A63B 60/54 20151001 |
Class at
Publication: |
473/336 |
International
Class: |
A63B 53/04 20060101
A63B053/04 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 25, 2008 |
JP |
2008-330932 |
Claims
1. A golf club head comprising: a head body; a weight member
attached to said head body; and fixing means for fixing said weight
member at any one of a plurality of attachment positions of said
head body, wherein the plurality of attachment positions are
located on a virtual cylindrical surface having an axis of a shaft
to be attached to the golf club head as a center.
2. The head according to claim 1, wherein a radius of the virtual
cylindrical surface is equal to a center-of-gravity length of said
head body without said weight member attached thereto.
3. The head according to claim 1, wherein said fixing means
comprises: a plurality of first screw portions which are provided
in a sole portion of said head body and define the plurality of
attachment positions; and a second screw portion which is provided
in said weight member and threadably engages with said first screw
portion.
4. The head according to claim 1, further comprising a rail portion
which is formed along a virtual line on the virtual cylindrical
surface in said sole portion of said body and defines the plurality
of attachment positions, wherein said fixing means fixes said
weight member at a given position on said rail portion.
5. The head according to claim 4, characterized in that said rail
portion comprises: a groove open at a lower part thereof, which is
formed along the virtual line and forms an accommodation space to
accommodate said weight member; a partitioned chamber closed at an
upper part thereof, which is formed along the virtual line in an
upper portion of said groove; a partitioning portion which is
provided between said groove and said partitioned chamber and
vertically partitions the space in said groove from said
partitioned chamber; and a slit which is formed along the virtual
line in said partitioned chamber and makes the space in said groove
communicate with said partitioned chamber, and said fixing means
comprises: a slide member which is accommodated in said partitioned
chamber such that it can move along the virtual line and connected
to said weight member through said slit; and screw portions which
are respectively provided in said slide member and said weight
member, and threadably engage with each other.
6. The head according to claim 1, wherein a change amount of
center-of-gravity angle of the golf club head caused by a
difference between the attachment positions used to fix said weight
member is not less than 3 degrees.
7. The head according to claim 1, further comprising a plurality of
said weight members having different weights.
8. The head according to claim 1, further comprising a vibration
damping member which is inserted between said head body and said
weight member at the attachment position.
9. The head according to claim 8, wherein said vibration damping
member is integrally provided in said weight member.
10. The head according to claim 1, wherein said weight member is
fixed to said sole portion of said head body, said sole portion has
a recess formed in the attachment position of said weight member,
and a depth of said recess is set such that a lowest portion of
said weight member fixed to said head body is positioned above a
lowest portion of said sole portion.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a golf club head.
[0003] 2. Description of the Related Art
[0004] There have been proposed golf club heads in which golfers
can change the position of a weight member attached to the golf
club head in accordance with their preference. Japanese Patent
Laid-Open Nos. 2001-137400, 2006-102235, and 2007-222257 disclose
putter heads in which the position of the weight member can be
changed. Japanese Utility Model Laid-Open No. 7-15067, Japanese
Patent Laid-Open No. 11-9742, and Japanese Utility Model
Registration No. 3127234 disclose wood type golf club heads in
which the position of the weight member can be changed.
[0005] When the position of the weight member is changed, the
center-of-gravity position of the golf club head changes. When the
center-of-gravity position changes, the characteristics of the golf
club head change and, for example, the height or lateral
directionality of flight of a hit ball, playability, and the like
change. Golfers can change the position of the weight member in
accordance with their preference.
[0006] When the position of the weight member is changed, however,
a plurality of characteristics of the golf club head may
simultaneously change. Some golfers may want to keep the
playability of the golf club unchanged but change other
characteristics of the golf club head.
SUMMARY OF THE INVENTION
[0007] It is an object of the present invention to provide a golf
club head in which the position of a weight member can be changed,
and a change in playability of the golf club is suppressed as much
as possible but other characteristics of the golf club head can be
changed by changing the position of the weight member.
[0008] According to the present invention, there is provided a golf
club head comprising a head body, a weight member attached to the
head body, and fixing means for fixing the weight member at any one
of a plurality of attachment positions of the head body, wherein
the plurality of attachment positions are located on a virtual
cylindrical surface having an axis of a shaft to be attached to the
golf club head as a center.
[0009] Further features of the present invention will become
apparent from the following description of exemplary embodiments
with reference to the attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a perspective view of a golf club head A according
to one embodiment of the present invention;
[0011] FIG. 2 is a view of the golf club head A seen from a hosel
portion 15 side in the direction of a line L1;
[0012] FIGS. 3A and 3B are sectional views of an attachment portion
131a taken along a line X-X in FIG. 1, in which FIG. 3A shows a
state in which a weight member 20 is detached and FIG. 3B shows a
state in which the weight member 20 is attached;
[0013] FIG. 4A is a sectional view showing the arrangement of an
attachment portion 131a according to the second embodiment of the
present invention;
[0014] FIG. 4B is a sectional view showing the arrangement of an
attachment portion 131a and a weight member 20 according to the
third embodiment of the present invention;
[0015] FIG. 5A is a perspective view of a rail portion 50 formed in
a sole portion 13;
[0016] FIG. 5B is a sectional view of the rail portion 50;
[0017] FIG. 5C is a sectional view of the weight member 20; and
[0018] FIG. 6 is a view for explaining a center-of-gravity
angle.
DESCRIPTION OF THE EMBODIMENTS
[0019] Preferred embodiments of the present invention will now be
described in detail in accordance with the accompanying
drawings.
First Embodiment
[0020] FIG. 1 is a perspective view of a golf club head A, and
particularly of a sole portion 13 according to one embodiment of
the present invention.
[0021] The golf club head A includes a head body 10 and a weight
member 20. The head body 10 is a hollow body, and its
circumferential wall constitutes a face portion 11 forming a golf
ball hitting surface, a crown portion 12 forming the top surface of
the golf club head A, the sole portion 13 forming the bottom
surface of the golf club head A, and a side portion 14 forming the
toe-side, heel-side, and back-side side surfaces of the golf club
head A. A hosel portion 15 to which a shaft is to be attached is
also provided in the head body 10. A line L1 represents the axis of
the shaft to be attached to the hosel portion 15, which is
substantially the same as the center axis of the hosel portion
15.
[0022] Although the golf club head A is a golf club head for a
driver, the present invention is applicable to wood type golf club
heads including a fairway wood and the like other than a driver,
utility type (hybrid type) golf club heads, and other hollow golf
club heads. The head body 10 is a hollow body in this embodiment,
but it may be solid.
[0023] The head body 10 can be assembled by joining a plurality of
parts. For example, the face portion 11 and the other part can be
formed as different members and joined to form the head body 10.
Also, the face portion 11, sole portion 13, and the other part can
be formed as different members and joined to form the head body 10.
The head body 10 can be made from e.g., a metal material including
a titanium metal material and stainless steel. The head body 10 can
be made from different materials. For example, it can be made from
a metal material and a carbon fiber material. As a carbon fiber
material, a carbon fiber reinforced resin (CFRP) is available.
[0024] A plurality of attachment portions 131a to 131d, which
define the attachment positions of the weight member 20, are formed
in the sole portion 13. Although four attachment portions 131a to
131d are provided in this embodiment, the number of the attachment
portions is not limited to four. The user of the golf club head A
can attach the weight member 20 to any one of the attachment
portions 131a to 131d. FIGS. 3A and 3B are sectional views of the
attachment portion 131a taken along a line X-X in FIG. 1, in which
FIG. 3A shows a state in which the weight member 20 is detached and
FIG. 3B shows a state in which the weight member 20 is attached.
Although the arrangement of the attachment portion 131a will be
described herein, the attachment portions 131b to 131d have the
same arrangement.
[0025] The attachment portion 131a forms a tube having a female
screw hole SC1. The weight member 20 has an axial male screw
portion SC2. The weight member 20 can be fixed to the head body 10
by threadably engaging the female screw hole SC1 and male screw
portion SC2 to each other.
[0026] A washer 30 is a vibration dampening member inserted between
the weight member 20 and the sole portion 13, which is a resin
member in this embodiment. The washer 30 serves to prevent loose
threadable engagement between the female screw hole SC1 and male
screw portion SC2, thereby preventing the weight member 20 from
falling easily, once fixed. The washer 30 also has an effect of
attenuating the vibration of the golf club head A that occurs at
impact. A resin material is preferable as such a vibration
dampening member, but materials of other kinds can also be
employed. Note that the washer 30 may be integrally provided in the
weight member 20. For example, the washer 30 may be fixed to the
weight member 20 in advance. Also, the surface of the weight member
20 may be covered with a resin material or the like.
[0027] Of the attachment portions 131a to 131d, the female screw
holes SC1 to which the weight member 20 is not attached can be
closed by attaching caps 40 shown in FIG. 3A. With this
arrangement, it is possible to prevent dust and the like from
entering the head body 10 through the female screw holes SC1. The
cap 40 is made from, e.g., a resin material, and detachably fitted
in the female screw hole SC1. In order to prevent dust and the like
from entering the head body 10 through the female screw holes SC1,
instead of using the caps 40, the female screw holes SC1 may be
closed at their upper ends.
[0028] The cap 40 is formed to have the same shape as the weight
member 20. The material of the cap 40 is selected such that its
weight substantially gives no influence on a change in
center-of-gravity position. The cap 40 may be formed to screw in
the female screw hole SC1.
[0029] The weight member 20 can be made from, e.g., a metal
material. As such a metal material, for example, tungsten, a
tungsten alloy, aluminum, an aluminum alloy, magnesium, and a
magnesium alloy are available. The weight member 20 may be made by,
e.g., mixing a metal powder with a viscoelastic material. In this
case, the vibration dampening effect of the golf club head A at
impact can improve. As such a viscoelastic material, for example,
NBR (acrylonitrile-butadiene rubber) is available.
[0030] The positions of the attachment portions 131a to 131d will
be described with reference to FIGS. 1 and 2. FIG. 2 is a view of
the golf club head A seen from the hosel portion 15 side in the
direction of the line L1, and particularly a perspective view of
the attachment portions 131a to 131d.
[0031] In FIGS. 1 and 2, a surface S is a virtual cylindrical
surface having the line L1 as the center. A line L2 is a virtual
line representing a part of the intersection line of the surface S
and sole portion 13. The attachment portions 131a to 131d are
located on the surface S, and particularly on the virtual line
L2.
[0032] In FIG. 2, a center-of-gravity position CG represents the
center-of-gravity position of the head body 10 without the weight
member 20 attached thereto, and a length r represents the
center-of-gravity length when the weight member 20 is not attached.
Note that the center-of-gravity length is the length of a
perpendicular line from the center-of-gravity position to the shaft
axis. In this embodiment, the radius of the surface S is set to be
the length r.
[0033] The effect obtained by arranging the attachment portions
131a to 131d on the surface S will be described next. When the
weight member 20 is fixed to any one of the attachment portions
131a to 131d, the center-of-gravity angle of the golf club head A
changes accordingly. In this specification, the center-of-gravity
angle is an angle formed by the vertical direction and face portion
when the shaft is horizontally supported while the golf club is
kept rotatable about the shaft. FIG. 6 is a view for explaining the
center-of-gravity angle. In FIG. 6, an angle .theta. formed by the
face portion 11 and a dashed line in the vertical direction that
passes the shaft axis L1 is the center-of-gravity angle. As shown
in FIG. 6, in case of a wood type club, the face portion 11
normally does not form a flat surface. Therefore, the direction of
the face portion 11 uses the tangential direction of the leading
edge of the face center as a reference.
[0034] For example, when the weight member 20 is attached to the
attachment portion 131a, the center-of-gravity angle of the golf
club head A becomes relatively large. When the center-of-gravity
angle becomes large, ball catchability relatively improves, and a
ball is easily hooked. When the weight member 20 is attached to the
attachment portion 131d, the center-of-gravity angle of the golf
club head A becomes relatively small. When the center-of-gravity
angle becomes small, golf ball catchability is relatively
suppressed, and a ball is easily sliced.
[0035] As described above, in this embodiment, the characteristics
of the golf club head A can be changed by selecting the attachment
portions 131a to 131d used to fix the weight member 20.
[0036] The playability of a golf club depends on the moment of
inertia of the golf club head about the shaft axis. That is, the
large moment of inertia of the golf club head about the shaft axis
discourages faster golf club head rotation through impact, and the
small moment of inertia of the golf club head about the shaft axis
encourages faster golf club head rotation through impact.
[0037] In this embodiment, the attachment portions 131a to 131d are
located on the surface S. Hence, regardless of the attachment
portions 131a to 131d used to attach the weight member 20, the
length between the attachment portion and line L1 (the length of
the perpendicular to the line L1) remains the same, as can be
understood from FIG. 2. Accordingly, an increase in moment of
inertia of the golf club head A about the line L1 caused by
attaching the weight member 20 remains the same regardless of the
attachment portions 131a to 131d used to attach the weight member
20, as long as the weight of the weight member 20 remains the same.
Therefore, the playability of the golf club does not change.
[0038] For this reason, although the center-of-gravity angle
changes depending on the attachment position of the weight member
20, the playability of the golf club hardly changes. Hence, a
golfer can selectively hook or slice a ball with little change in
his or her hitting manner.
[0039] As described above, in this embodiment, a change in
playability of the golf club having the golf club head A can be
suppressed as much as possible but other characteristics of the
golf club head A can be changed by changing the attachment position
of the weight member 20.
[0040] Advanced players have a sharp sense for golf clubs.
Accordingly, the farther the attachment position of the weight
member 20 is from the center-of-gravity position CG of the head
body 10, the more readily the advanced players may recognize the
presence of the weight member 20 in regard to the playability of
golf club, and feel a sense of discomfort from the swing feel of
golf club. In order to reduce the sense of discomfort, the radius
of the virtual cylindrical surface S is desirably equal to or
smaller than the length r as the center-of-gravity length of the
center-of-gravity position CG of the head body 10 (e.g., length
r.gtoreq.radius of virtual cylindrical surface S.gtoreq.length r-5
mm), as in this embodiment. Optimally, the radius of the virtual
cylindrical surface S is equal to the length r, as in this
embodiment.
[0041] Although the one weight member 20 is used in this
embodiment, one of a plurality of the weight members 20 having
different weights may be selectively fixed to the head body 10.
With this arrangement, it becomes possible to widen the selection
range of center-of-gravity position and center-of-gravity depth of
the golf club head A and to increase their choices as well. In this
case, the two or more weight members 20 may simultaneously be fixed
to the head body 10.
[0042] The change amount of center-of-gravity angle of the golf
club head A caused by the difference between the attachment
portions 131a to 131d used to fix the weight member 20, for
example, the difference in center-of-gravity angle between a case
in which the weight member 20 is attached to the attachment portion
131a and a case in which the weight member 20 is attached to the
attachment portion 131d, is preferably 3.degree. or more. When the
difference in center-of-gravity angle is 3.degree. or more, a
golfer can more clearly feel the change in characteristics of the
golf club head caused by the change in center-of-gravity
position.
Second Embodiment
[0043] FIG. 4A is a sectional view showing another arrangement
example of the attachment portion 131a, which corresponds to the
sectional view of an attachment portion 131a taken along the line
X-X in FIG. 1. The same components as in the golf club head A of
the above-described first embodiment are denoted by the same
reference numerals below, and a description thereof will not be
repeated. Only components different from those of the golf club
head A will be described. Although the attachment portion 131a will
be described herein, attachment portions 131b to 131d have the same
arrangement.
[0044] In this embodiment, a recess 132 to accommodate a weight
member 20 is provided in the attachment portion 131a. The depth of
the recess 132 is set such that the lowest portion of the weight
member 20 fixed to a head body 10 is positioned above the lowest
portion of a sole portion 13.
[0045] With this arrangement, as shown in FIG. 4A, the weight
member 20 does not project from the sole portion 13. Accordingly,
it is possible to prevent the weight member 20 from catching the
ground upon hitting a ball.
Third Embodiment
[0046] FIG. 4B is a sectional view showing another arrangement
example of the attachment portion 131a and weight member 20, which
corresponds to the sectional view of an attachment portion 131a
taken along the line X-X in FIG. 1. The same components as in the
golf club head A of the above-described first embodiment are
denoted by the same reference numerals below, and a description
thereof will not be repeated. Only components different from those
of the golf club head A will be described. Although the attachment
portion 131a will be described herein, attachment portions 131b to
131d have the same arrangement.
[0047] In this embodiment, an axial male screw portion SC3 is
provided in the attachment portion 131a, and a female screw hole
SC4 which threadably engages with the male screw portion SC3 is
provided in a weight member 20. The attachment portion 131a has an
internal space to accommodate the weight member 20, thereby
preventing the weight member 20 from projecting from a sole portion
13, as in the above-described second embodiment.
[0048] In this manner, the screw portion on the sole portion 13
side and that on the weight member 20 side may be a male screw and
female screw, respectively, and vice versa.
Fourth Embodiment
[0049] In the above-described first to third embodiments, the
weight member 20 can be fixed at a plurality of positions separated
from each other. However, a weight member 20 may be fixable at a
given position on a vertical line included in a surface S. With
this arrangement, it is possible to more finely adjust the
center-of-gravity position and center-of-gravity depth of the golf
club head.
[0050] FIG. 5A is a perspective view of a rail portion 50 formed in
a sole portion 13, FIG. 5B is a sectional view of the rail portion
50, and FIG. 5C is a sectional view of the weight member 20. The
same components as in the golf club head A of the above-described
first embodiment are denoted by the same reference numerals below,
and a description thereof will not be repeated. Only components
different from those of the golf club head A will be described.
[0051] The rail portion 50 extending along a virtual line L2 (see
FIG. 1) included in the surface S is formed in the sole portion 13.
As described below, the rail portion 50 guides the movement of the
weight member 20. The rail portion 50 includes a groove 51 formed
by recessing the sole portion 13 and open at its lower part, and a
partitioned chamber 52 formed in the upper portion of the groove
51. Both the groove 51 and partitioned chamber 52 are formed along
the above-described virtual line L2. Note that although not shown
in FIG. 5A, the each end portion of the rail portion 50 is
appropriately closed.
[0052] The groove 51 has a pair of side walls 13a and a pair of
partitioning portions 13b formed by bending the side walls 13a. The
partitioning portions 13b are located between the groove 51 and
partitioned chamber 52, thereby vertically partitioning them. The
pair of the partitioning portions 13b are spaced apart from each
other to form a slit 53. The groove 51 accommodates the weight
member 20. The depth of the groove 51 is set such that the lowest
portion of the weight member 20 fixed to the head body 10 is
positioned above the lowest portion of the sole portion 13. With
this arrangement, the weight member 20 does not project from the
sole portion 13, and therefore it is possible to prevent the weight
member 20 from catching the ground upon hitting a ball.
[0053] The partitioned chamber 52 is formed by joining the lower
ends of a lid member 54 having a U-shaped cross section to the
partitioning portions 13b. The upper part of the partitioned
chamber 52 is closed by the lid member 54.
[0054] The partitioned chamber 52 accommodates a slide member 55.
The slide member 55 is sized such that it cannot rotate in the
partitioned chamber 52 and, for example, has a square shape when
viewed from above. An axial male screw portion SC5 that passes the
slit 53 is integrally connected to the slide member 55. A female
screw hole SC6 which threadably engages with the male screw portion
SC5 is formed in the weight member 20. The width of the weight
member 20 is larger than that of the slit 53 in the widthwise
direction.
[0055] In this embodiment with the above-described components, when
the male screw portion SC5 threadably engages with the female screw
hole SC6, the slide member 55 and weight member 20 sandwich the
partitioning portions 13b, thereby fixing the weight member 20 to
the head body 10. A washer 30 inserted between the partitioning
portions 13b and weight member 20 prevents the loose threadable
engagement between the male screw portion SC5 and female screw hole
SC6.
[0056] When changing the position of the weight member 20, the
threadable engagement between the male screw portion SC5 and female
screw hole SC6 is loosened, and the slide member 55 and the weight
member 20 are moved. Since these members are guided by the rail
portion 50 during movement, their positions can be easily changed.
By threadably engaging the male screw portion SC5 with the female
screw hole SC6 at a desired position, the weight member 20 can be
fixed.
[0057] As described above, in this embodiment, the weight member 20
can be fixed at a given position on the virtual line L2, and
therefore it is possible to more finely adjust the
center-of-gravity position and center-of-gravity depth of the golf
club head. Note that in this embodiment, the center-of-gravity
position of the head body 10 is defined as a center-of-gravity
position CG of the head body 10 without the weight member 20 and
slide member 55. Also, in this embodiment, since the weight member
20 can be completely detached from the slide member 55, one of a
plurality of the weight members 20 having different weights may be
selectively fixed to the head body 10.
[0058] In this embodiment, since the rail portion 50 is enclosed by
a closing member 141, the wall portion 16, and the lid member 54,
it is possible to prevent dust and the like from entering the head
body 10 through the rail portion 50.
[0059] Note that the structure of the rail portion 50 is not
limited to that shown in FIGS. 5A and 5B, and any structure can be
used as long as the weight member 20 can be moved and fixed at a
given position.
[0060] While the present invention has been described with
reference to exemplary embodiments, it is to be understood that the
invention is not limited to the disclosed exemplary embodiments.
The scope of the following claims is to be accorded the broadest
interpretation so as to encompass all such modifications and
equivalent structures and functions.
[0061] This application claims the benefit of Japanese Patent
Application No. 2008-330932, filed Dec. 25, 2008, which is hereby
incorporated by reference herein in its entirety.
* * * * *